fix: harden channel retry attribution and operations UI

gateway/internal/queue/messages.go

@@ -79,6 +79,7 @@ type Retry struct {
 
 type SubmitResult struct {
 	Envelope
+	SubmitID         string                `json:"submitId"`
 	SequenceID       uint32                `json:"sequenceId"`
 	GatewayMessageID string                `json:"gatewayMessageId"`
 	SubmitStatus     string                `json:"submitStatus"`

gateway/internal/queue/messages_test.go

@@ -67,3 +67,20 @@ func TestSubmitCommandUnmarshalsQueuePriority(t *testing.T) {
 		t.Fatalf("unexpected extension digits: %d", command.CMPP.ExtensionDigits)
 	}
 }
+
+func TestSubmitResultMarshalsSubmitID(t *testing.T) {
+	payload, err := json.Marshal(SubmitResult{SubmitID: "submit-1"})
+	if err != nil {
+		t.Fatalf("marshal submit result: %v", err)
+	}
+	if string(payload) == "" || !json.Valid(payload) {
+		t.Fatalf("invalid submit result JSON: %s", payload)
+	}
+	var decoded map[string]any
+	if err := json.Unmarshal(payload, &decoded); err != nil {
+		t.Fatalf("unmarshal submit result: %v", err)
+	}
+	if decoded["submitId"] != "submit-1" {
+		t.Fatalf("submitId = %v, want submit-1", decoded["submitId"])
+	}
+}

gateway/internal/upstream/manager.go

@@ -1284,6 +1284,7 @@ func submitResult(cmd queue.SubmitCommand, sequenceID uint32, gatewayMessageID s
 			ChannelID:     cmd.ChannelID,
 			CreatedAt:     time.Now().UTC(),
 		},
+		SubmitID:         cmd.SubmitID,
 		SequenceID:       sequenceID,
 		GatewayMessageID: gatewayMessageID,
 		SubmitStatus:     status,

gateway/internal/upstream/submit_packet_test.go

@@ -41,6 +41,20 @@ func TestSubmitRequestPacketUsesCMPP2PacketForCMPP20Channel(t *testing.T) {
 	}
 }
 
+func TestSubmitResultKeepsCommandSubmitID(t *testing.T) {
+	cmd := submitCommandForPacketTest("2.0")
+	cmd.SubmitID = "submit-attempt-2"
+
+	result := submitResult(cmd, 42, "9001", "accepted", "", "")
+
+	if result.SubmitID != cmd.SubmitID {
+		t.Fatalf("SubmitID = %q, want %q", result.SubmitID, cmd.SubmitID)
+	}
+	if result.ChannelID != cmd.ChannelID || result.MessageID != cmd.MessageID {
+		t.Fatalf("unexpected result envelope: %+v", result.Envelope)
+	}
+}
+
 func TestSubmitRequestPacketUsesCMPP3PacketForCMPP30Channel(t *testing.T) {
 	conn := &connection{config: queue.UpstreamConfig{CMPPVersion: "3.0", Account: "ljcs02"}}
 	cmd := submitCommandForPacketTest("3.0")